WINGs/mywidget.c

   1 /*
   2  * Demo user widget for WINGs.
   3  *
   4  *
   5  * Copyright (c) 1998 Alfredo K. Kojima
   6  */
   7
   8
   9 /*
  10  *
  11  * Include the WINGs private data header.
  12  *
  13  *
  14  */
  15 #include "WINGsP.h"
  16
  17 /*
  18  * Our public header.
  19  */
  20 #include "mywidget.h"
  21
  22 /*
  23  * Define the widget "class"
  24  */
  25 typedef struct W_MyWidget {
  26     /* these two fields must be present in all your widgets in this
  27      * exact position */
  28     W_Class widgetClass;
  29     WMView *view;
  30
  31     /* put your stuff here */
  32     char *text;
  33
  34 } _MyWidget;
  35
  36
  37
  38
  39 /* some forward declarations */
  40
  41 static void destroyMyWidget(_MyWidget *mPtr);
  42 static void paintMyWidget(_MyWidget *mPtr);
  43
  44
  45 static void handleEvents(XEvent *event, void *data);
  46 static void handleActionEvents(XEvent *event, void *data);
  47
  48
  49
  50 /*
  51  * Some procedures you might want to override. Don't forget to call
  52  * the equivalent view procedure after (or before) doing your stuff.
  53  * See the source for the other widgets to see how to use.
  54  * You won't need to use this most of the time.
  55  */
  56 static W_ViewProcedureTable _MyWidgetViewProcedures = {
  57         NULL,
  58         NULL,
  59         NULL
  60 };
  61
  62
  63 /* our widget class ID */
  64 static W_Class myWidgetClass = 0;
  65
  66
  67 /*
  68  * Initializer for our widget. Must be called before creating any
  69  * instances of the widget.
  70  */
  71 W_Class
  72 InitMyWidget(WMScreen *scr)
  73 {
  74     /* register our widget with WINGs and get our widget class ID */
  75     if (!myWidgetClass) {
  76         myWidgetClass = W_RegisterUserWidget(&_MyWidgetViewProcedures);
  77     }
  78
  79     return myWidgetClass;
  80 }
  81
  82
  83 /*
  84  * Our widget fabrication plant.
  85  */
  86 MyWidget*
  87 CreateMyWidget(WMWidget *parent)
  88 {
  89     MyWidget *mPtr;
  90
  91     /* allocate some storage for our new widget instance */
  92     mPtr = wmalloc(sizeof(MyWidget));
  93     /* initialize it */
  94     memset(mPtr, 0, sizeof(MyWidget));
  95
  96     /* set the class ID */
  97     mPtr->widgetClass = myWidgetClass;
  98
  99     /*
 100      * Create the view for our widget.
 101      * Note: the Window for the view is only created after the view is
 102      * realized with W_RealizeView()
 103      *
 104      * Consider the returned view as read-only.
 105      */
 106     mPtr->view = W_CreateView(W_VIEW(parent));
 107     if (!mPtr->view) {
 108         free(mPtr);
 109         return NULL;
 110     }
 111     /* always do this */
 112     mPtr->view->self = mPtr;
 113
 114     /*
 115      * Intercept some events for our widget, so that we can handle them.
 116      */
 117     WMCreateEventHandler(mPtr->view, ExposureMask /* this allows us to know when we should paint */
 118                          |StructureNotifyMask, /* this allows us to know things like when we are destroyed */
 119                          handleEvents, mPtr);
 120
 121     /*
 122      * Intercept some other events. This could be merged with the above
 123      * call, but we separate for more organization.
 124      */
 125     WMCreateEventHandler(mPtr->view, ButtonPressMask,handleActionEvents, mPtr);
 126
 127     return mPtr;
 128 }
 129
 130
 131
 132 /*
 133  * Paint our widget contents.
 134  */
 135 static void
 136 paintMyWidget(_MyWidget *mPtr)
 137 {
 138     W_Screen *scr = mPtr->view->screen;
 139     WMColor *color;
 140
 141
 142     if (mPtr->text) {
 143
 144         color = WMWhiteColor(scr);
 145
 146         W_PaintText(mPtr->view, mPtr->view->window, scr->normalFont,  0, 0,
 147                     mPtr->view->size.width, WACenter, W_GC(color),
 148                     False, mPtr->text, strlen(mPtr->text));
 149
 150         WMReleaseColor(color);
 151     }
 152 }
 153
 154
 155
 156 static void
 157 handleEvents(XEvent *event, void *data)
 158 {
 159     _MyWidget *mPtr = (_MyWidget*)data;
 160
 161
 162     switch (event->type) {
 163      case Expose:
 164         if (event->xexpose.count!=0)
 165             break;
 166         paintMyWidget(mPtr);
 167         break;
 168
 169      case DestroyNotify:
 170         destroyMyWidget(mPtr);
 171         break;
 172
 173     }
 174 }
 175
 176
 177 static void
 178 handleActionEvents(XEvent *event, void *data)
 179 {
 180     _MyWidget *mPtr = (_MyWidget*)data;
 181
 182     switch (event->type) {
 183      case ButtonPress:
 184         XBell(mPtr->view->screen->display, 100);
 185         XBell(mPtr->view->screen->display, 100);
 186         break;
 187     }
 188 }
 189
 190
 191 void
 192 SetMyWidgetText(MyWidget *mPtr, char *text)
 193 {
 194     CHECK_CLASS(mPtr, myWidgetClass);
 195
 196     if (mPtr->text)
 197         free(mPtr->text);
 198
 199     mPtr->text = wstrdup(text);
 200
 201     if (W_VIEW_MAPPED(mPtr->view)) {
 202         paintMyWidget(mPtr);
 203     }
 204 }
 205
 206
 207
 208 static void
 209 destroyMyWidget(_MyWidget *mPtr)
 210 {
 211     /*
 212      * Free all data we allocated for our widget.
 213      */
 214
 215     if (mPtr->text)
 216         free(mPtr->text);
 217
 218     free(mPtr);
 219 }
 220
 221